How to write multiple geometries per feature to Interlis2

In an Interlis Model provided by the state, I have to write two geometries per feature to Interlis2. Using this FME article (Writing to Database Tables that contain Multiple Geometry Columns) I was able to read the multiple geometries from Oracle. In the database I have a view with both geometries (point and additional polygon). The linked article only provides information for writing multiple geometries to databases. In the Interlis-Writer (ili2fme) I don't have any settings for treating features with multiple geometries. Is it even possible?

The interlis model needs the "primary" geometry (point) to be written as standard geometry, while the secondary geometry (polygon) should be written into a specifiy attribute "Detailgeometrie". How can I tell FME to write the secondary geometry to a specific attribute?

Attached is the interlis-model (ili) provided by state.

The class with multiple geometries is "InfrastrukturKnoten" with its optional attribute "Detailgeometrie".